Compilare: main.cpp:7:0: warning: "INFINITY" redefined #define INFINITY 0x3f3f3f3f In file included from /usr/include/math.h:41:0, from /usr/include/c++/6/cmath:45, from /usr/include/c++/6/math.h:36, from main.cpp:4: /usr/include/x86_64-linux-gnu/bits/inf.h:26:0: note: this is the location of the previous definition # define INFINITY (__builtin_inff()) main.cpp: In function 'int main()': main.cpp:31:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("smin.in", "r", stdin); ^ main.cpp:32:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("smin.out", "w", stdout); ^ main.cpp:34:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:38:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^